“Today was a great day,” Mayweather said. “The atmosphere was remarkable, unbelievable.”

Even though Mayweather fans were loud, those in support of Alvarez waved the flag of Mexico and hoisted signs in support.

“I thank you for the support from the bottom of my heart and on Sept. 14, everybody is going to be surprised,” said Alvarez, who went back and forth in both English and Spanish.

Tickets for their Sept. 14 fight started selling on Tuesday and have sold out.

“The first record has been broken,” said Richard Schaefer, CEO of Golden Boy Promotions to the crowd. “The gate is sold out in Las Vegas, generating a new record live gate number for any boxing event in Las Vegas.”

Mayweather participated in the 1996 Summer Olympics in Atlanta where he lost the featherweight division to Serafim Todorov of Bulgaria and received the bronze medal.

“It was rough for me when I took that loss, but I think it was a learning experience to make me become hungrier and dedicate myself more to the sport of boxing,” said Mayweather, who has 26 knockouts.

To this day Mayweather hasn’t lost since and keeps a 44-0 record while Alvarez has a record of 42-0-1 with 30 KOs.

“I’m going to work very hard,” said Alvarez. “Floyd Mayweather is the best fighter in the world at this time, but all of us have our time. Now is my time.”

Mayweather was last in Atlanta during the NCAA Final Four, promoting his fight with Robert Guerrero.

De La Hoya, who lost to Mayweather, said Alvarez’s approach to fighting is unlike any who have fought against Mayweather.

“The only thing he tells me is people are going to be surprised with my speed,” De La Hoya said. “People are going to be surprised with my boxing ability. That’s very interesting to me because I’ve never heard that (from) any other opponent (of Mayweather’s), including myself. When I was with Floyd, I wanted to chop his head off and go for the kill. Well, obviously then the game plan goes out the door.”

Mayweather says everyone has a game plan, but none have unlocked the mystery to beating him.

“You know what you’re facing when you face me,” Mayweather said. “You’re facing the best so you can’t make any mistakes. Got to have your ‘A’ game on.”

Atlanta resident and boxing legend Evander Holyfield says Manny Pacquiao is the only fighter that can seriously challenge Mayweather.

Alvarez isn’t busy enough in the ring to beat Mayweather, said Holyfield.

“He’s young, but the point of the matter is he doesn’t throw enough punches,” Holyfield said. “Floyd knows how to win. People are looking at 36 years old, but that doesn’t matter if you’re taking care of yourself.”

Pacquiao hasn’t been in the ring since last year when Juan Manual Marquez knocked him out.

“Pacquiao throws punches in all different ways,” Holyfield said. “On balance. Off balance. He threw a lot of punches.”

The fight between Mayweather and Alvarez will take place at the MGM Grand Hotel & Casino.